1. Field of the Invention
This invention relates to check valves for controlling the direction of flow of a fluid within a tube. More particularly, this invention relates to check valve clamps for clamping the check valve into the opened end of a tube allowing a fluid to be forced into the tube and checked from flowing out of the tube.
2. Description of the Background Art
Presently, there exist many types of check valves designed to be inserted within the end of a tube to allow the flow of a fluid into the tube while checking or preventing the fluid from flowing out of the tube. Typical examples of such check valves are disclosed in U.S. Pat. No. 3,831,629, in U.S. Pat. No. 4,602,655, and in U.S. patent application, Ser. No. 06/867,319, filed May 23, 1986, now U.S. Pat. No. 4,681,132 the disclosure of each of which is hereby incorporated by reference herein. Each of these check valves is commonly referred to as a catheter valve and designed to be used in the proximal end of an inflation tube of a catheter, endotracheal tube, or the like.
More specifically, most catheters include an inflatable balloon or cuff at its distal end which is inflated via the inflation tube once the catheter or endotracheal tube is properly positioned within the patient's trachea, thereby securing the catheter or endotracheal tube into position. The catheter check valve, being positioned in the proximal end of the inflation tube, allows the inflatable cuff to be inflated through the use of a syringe and then, once inflated, the catheter check valve prevents the air from escaping causing deflation of the cuff. U.S. Pat. No. 4,617,015, the disclosure of which is hereby incorporated by reference herein, more particularly discloses the operation of a catheter check valve used in conjunction with an endotracheal tube.
It has always been desirable to completely and rigidly seal the catheter check valve within the end of the inflation tube to prevent air leakage therebetween even when the check valve and tube are roughly handled. In U.S. Pat. No. 3,831,629, the check valve is secured within the end of the tube by means of a frustro-conical retaining sleeve or cap. Specifically, the tube is threaded through the opening in the cap and then, after the valve is forced into the end of the tube, the cap is slid back along the tube and fitted over the end of the check valve to compress and sealingly secure the tube therebetween. In U.S. Pat. No. 4,602,655, the check valve is secured and sealed within the end of the tube by means of a flange mounting formed integrally with the body of the check valve allowing the end of the tube to be slid into position between the opened end of the flange and the valve body. After the tube is properly positioned between the flange and the valve body, the flange is annularly crimped to rigidly secure and seal the check valve into the end of the tube. Finally, another type of retaining sleeve or clamp comprises an annular sleeve having an inwardly disposed annular groove formed upon its lumen which mates with a corresponding annular protrusion extending about the outer surface of the body of the check valve. During installation, the check valve is forced into the end of the tube and then the sleeve is forced over the end of the tube containing the check valve, until the annular groove formed in the sleeve is aligned in the same plane as the annular protrusion extending from the body of the check valve. The tube positioned therebetween is thus compressed to form a rigid seal with the check valve.
All of the devices for installing a catheter check valve within the end of a tube as disclosed above have been widely accepted throughout the medical and other fields. However, the sleeve or clamp disclosed in U.S. Pat. No. 3,831,629 is difficult to implement in a production environment because the sleeve must be fitted over the tube before the check valve is inserted into the end of the tube. The integral mounting flange of the check valve disclosed in U.S. Pat. No. 4,602,655 and the removable sleeve of the latter type described above, are both adaptable to production environments for automatic assembly. However, more rigid retention of the check valve within the end of the tube is desirable. Specifically, experience has shown with the latter type of sleeve or clamp, adequate force may be imparted to the valve body during inflation via the syringe, that the annular groove of the sleeve is forced out of position in alignment with the annular protrusion of the valve body. When such occurs, it is obvious that the check valve is no longer rigidly secured within the end of the tube.
Therefore, it is an object of this invention to provide an apparatus which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the check valve art.
Another object of this invention is to provide means for rigidly and sealingly securing a check valve within the end of a tube.
Another objeot of this invention is to provide a clamping sleeve for rigidly and sealingly securing a check valve within the end of a tube which may be assembled in production quantities using conventional production line assembly equipment.
Another object of this invention is to provide a clamping sleeve which rigidly and sealingly secures a check valve within the end of a tube and is not releasable therefrom even when excessive pressure is applied to the valve body by a syringe or otherwise.
The foregoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.